JPH07299675A - Automatic screw driving machine - Google Patents
Automatic screw driving machineInfo
- Publication number
- JPH07299675A JPH07299675A JP9161794A JP9161794A JPH07299675A JP H07299675 A JPH07299675 A JP H07299675A JP 9161794 A JP9161794 A JP 9161794A JP 9161794 A JP9161794 A JP 9161794A JP H07299675 A JPH07299675 A JP H07299675A
- Authority
- JP
- Japan
- Prior art keywords
- screw tightening
- screw
- work
- tightening head
- carrier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Manipulator (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は産業用ロボット等のキャ
リア部にねじ締めドライバを持たせた自動ねじ締め機に
関するもので、作業時間を短縮できるようにするもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightening machine having a screw tightening driver in a carrier portion of an industrial robot or the like, and is capable of shortening a working time.
【０００２】[0002]
【従来の技術】従来の自動ねじ締め機は、ねじをワーク
に締めるねじ締めヘッドと、ねじ締めヘッドへねじを供
給するフィーダと、ねじ締めヘッドあるいはワークを移
動するキャリア部と、キャリア部を所定の教示位置へ位
置決めしねじ締めヘッドを動作させる制御装置から構成
される。ねじ締めヘッドは、ねじをワークに締めるため
のねじ締めドライバとこのねじ締めドライバを昇降動さ
せるスライド部からなる。キャリア部は、ロータリエン
コーダ付きモータに直結されたボールネジを介してモー
タの回転角分だけ移動する。2. Description of the Related Art A conventional automatic screw tightening machine has a screw tightening head for tightening a screw on a work, a feeder for supplying the screw to the screw tightening head, a carrier part for moving the screw tightening head or the work, and a carrier part. The control device for positioning the screw tightening head at the taught position and operating the screw tightening head. The screw tightening head includes a screw tightening driver for tightening a screw on a work and a slide portion for moving the screw tightening driver up and down. The carrier unit moves by a rotation angle of the motor via a ball screw directly connected to the motor with the rotary encoder.
【０００３】上記のように構成された従来の自動ねじ締
め機は、制御装置がモータを駆動しキャリア部を所定の
教示位置へ位置決めし、位置決め完了後、キャリア部の
位置をいわゆるサーボロック動作により位置決め点に保
持したままねじ締めドライバを回転させると共にスライ
ド部を駆動し、ねじをワークに押し付けながらねじ締め
作業を行い、ねじ締めが完了すると、フィーダからねじ
締めヘッドへねじが送られ、制御装置は次のねじ締め位
置へキャリア部を移動し、ねじをワークに締めるという
一連の動作を繰り返してねじ締め作業を行うものであっ
た。In the conventional automatic screw tightener constructed as described above, the control device drives the motor to position the carrier portion at a predetermined teaching position, and after the positioning is completed, the position of the carrier portion is changed by a so-called servo lock operation. While holding the screw at the positioning point, rotate the screw tightening driver and drive the slide part to perform the screw tightening work while pressing the screw against the work.When the screw tightening is completed, the screw is sent from the feeder to the screw tightening head and the controller Has carried out the screw tightening work by repeating a series of operations of moving the carrier part to the next screw tightening position and tightening the screw to the work.
【０００４】[0004]
【発明が解決しようとする課題】従来の自動ねじ締め機
は、上記のようにねじ締めヘッドあるいはワークを移動
するキャリア部を一旦位置決めした後、ねじ締めヘッド
を動作させる制御方法であったため、ねじ締めヘッドの
下降時間が全てねじ締め作業時間に加わり、ねじ締め作
業に時間がかかるという欠点があった。Since the conventional automatic screw tightening machine is a control method in which the screw tightening head or the carrier part for moving the work is once positioned as described above, the screw tightening head is operated. There is a drawback in that the time required for descending the tightening head is all added to the screw tightening work time, and the screw tightening work takes time.
【０００５】また従来の自動ねじ締め機は、ワークのね
じ下穴精度が悪い場合、位置決め完了後ねじ締めドライ
バのビットの中心とワークのねじ下穴の中心が多少ずれ
ていても、キャリア部の位置が保持されたままでねじ締
め作業を行う。このようなねじ締め作業の場合、制御装
置はねじ締めドライバ及びワークを固定したキャリア部
の各々の位置を保持するように動作し、ねじ締めドライ
バ用モータへ流れる電流が増大し過電流遮断用に設けた
ヒューズが切れるという問題があった。更に、キャリア
部の位置を保持したままで強引にねじ締め作業を行うの
でねじ浮き等のねじ締め不良が起き易く、信頼性が高く
安定した自動ねじ締め動作が得られず、作業能率が悪か
った。Further, in the conventional automatic screw tightening machine, when the precision of the screw hole of the workpiece is poor, even if the center of the bit of the screw tightening driver and the center of the screw hole of the workpiece are slightly deviated after positioning is completed, Perform the screw tightening work while maintaining the position. In the case of such screw tightening work, the control device operates so as to hold each position of the screw tightening driver and the carrier part to which the work is fixed, and the current flowing to the screw tightening driver motor increases to prevent overcurrent interruption. There was a problem that the provided fuse was blown. Furthermore, since the screw tightening work is forcibly performed while holding the position of the carrier part, screw tightening failure such as screw floating is likely to occur, and reliable and stable automatic screw tightening operation cannot be obtained, resulting in poor work efficiency. .
【０００６】本発明の一つの目的は、上記した従来技術
の欠点に鑑み、位置決め完了後にねじ締めヘッドが下降
動作を開始する無駄を排除し、ねじ締め作業時間を短縮
した自動ねじ締め機を提供することにある。本発明の他
の目的は、キャリア部の位置の保持を解除させる機能を
持たせ、ねじ下穴の位置精度が悪いワークに対してもね
じ締め不良をなくし、ねじ締めの信頼性を向上させた自
動ねじ締め機を提供することである。In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide an automatic screw tightening machine which eliminates the waste of the screw tightening head starting the descending operation after the completion of positioning and shortens the screw tightening work time. To do. Another object of the present invention is to provide a function of releasing the holding of the position of the carrier portion, to eliminate the screw tightening defect even for a work having a poor position accuracy of the screw pilot hole, and to improve the reliability of the screw tightening. The purpose is to provide an automatic screw tightener.
【０００７】[0007]
【課題を解決するための手段】上記目的は、キャリア部
を所定の教示位置へ位置決めする以前にねじ締めヘッド
を動作させ、ねじ締めヘッド動作条件を設定変更できる
操作部を備えた制御装置を設けることにより達成され
る。また上記の他の目的は、キャリア部の位置の保持と
位置保持の解除を作業プログラムで選択設定できる制御
装置を設けることにより達成される。The object of the present invention is to provide a control device provided with an operating portion for operating the screw tightening head before positioning the carrier part at a predetermined teaching position and changing the screw tightening head operating condition. It is achieved by Further, the above-described other object is achieved by providing a control device capable of selectively setting the holding of the position of the carrier part and the release of the position holding by a work program.
【０００８】[0008]
【作用】上記のように構成された制御装置は、ねじ締め
ヘッドを移動するキャリア部の位置と所定の教示位置と
の差がねじ締めヘッド動作許可範囲以内になった時、ね
じ締めヘッドを動作開始させる。また上記のように構成
された制御装置はキャリア部が所定の教示位置に停止す
るまでの時間を所定の速度パターンからサンプリング周
期毎に計算し、この時間がねじ締めヘッド動作許可時間
以内になった時ねじ締めヘッドを動作させる。また上記
の制御装置は、作業プログラムにより教示したステップ
内容に対応して動作し、ステップの教示内容が位置保持
有の場合は位置決め完了後位置決め点でキャリア部の位
置保持動作を行い、ステップの教示内容が保持解除の場
合はキャリア部の位置保持を解除させる。The control device configured as described above operates the screw tightening head when the difference between the position of the carrier portion that moves the screw tightening head and the predetermined teaching position is within the screw tightening head operation permission range. Let it start. Further, the control device configured as described above calculates the time until the carrier portion stops at the predetermined teaching position for each sampling cycle from the predetermined speed pattern, and this time is within the screw tightening head operation permission time. When operating the screw tightening head. Further, the above control device operates in accordance with the step contents taught by the work program. If the position teaching is included in the teaching contents of the step, the position holding operation of the carrier portion is performed at the positioning point after the positioning is completed, and the teaching of the step is taught. When the content is released, the carrier position is released.
【０００９】[0009]
【実施例】本発明の具体的な実施例を以下図面に基づい
て詳細に説明する。図１は本発明の実施例に好適な自動
ねじ締め機３０の斜視図を示したものである。自動ねじ
締め機３０は、ねじ１６をワーク１７に締めるねじ締め
ヘッド２０と、ねじ圧送ホ−ス１９を介してねじ１６を
ねじ締めヘッド２０へ供給するフィーダ１２と、ねじ締
めヘッド２０を図示のＸ軸方向に移動するキャリア部１
５Ｘと、ワーク１７を図示のＹ軸方向に移動するキャリ
ア部１５Ｙと、キャリア部１５Ｘ、１５Ｙ（以下キャリ
ア部１５Ｘと１５Ｙをキャリア部１５と総称する）を所
定の教示位置へ位置決めしねじ締めヘッド２０を動作さ
せる制御装置１４から構成される。ねじ締めヘッド２０
は、ねじ１６をワーク１７に締めるためのねじ締めドラ
イバ１０とこのねじ締めドライバ１０を図示のＺ軸方向
に内蔵のエアシリンダまたはモータ等により昇降させる
スライド部９からなる。キャリア部１５は、夫々キャリ
ア部１５Ｘ用及びキャリア部１５Ｙ用のＤＣモータ３、
６（以下モータという）に直結されたボールネジを介し
てモータ３、６の回転角分だけ移動する。１３は自動ね
じ締め機３０にねじ締め作業の教示や制御動作の設定を
行うためのキーボード、表示部等から成る操作部であ
る。自動ねじ締め機３０の制御装置１４のブロック図を
示す図２において、図１と同一の機能の部分には同一の
番号が付してあり、制御装置１４は、モータ３、６を夫
々駆動するモータドライブ回路２、５と、モータドライ
ブ回路２、５によるモータ３、６の駆動、非駆動を制御
する制御線（以下ＳＤ信号という）３１と、モータ３、
６に夫々直結されたエンコーダ５０、５１から出力され
るパルスをカウントするカウンタ４、７と、ねじ締めド
ライバ１０を駆動するドライバ駆動部１１と、作業プロ
グラム等を入力する操作部１３と、ＲＯＭ２９、ＲＡＭ
２８、Ｉ／ＯポートＰ１、Ｐ２、Ｐ３、Ｐ４、Ｐ５及び
Ｐ１０とパラレルＩ／ＯポートＰＤ１、ＰＤ２及びＰＤ
３をワンチップ化し前記モータ３、６とねじ締めヘッド
２０等の制御処理を時分割によるマルチ処理を実行する
ＣＰＵ１から構成される。ＣＰＵ１のポートＰ５はフィ
ーダ１２に圧送指令を出力する出力端子であり、ポート
Ｐ３は、スライド部９がエアシリンダにより動作する場
合はエアシリンダに圧縮空気の供給・排気を制御するエ
アバルブの制御線となり、スライド部９が電気モータに
より動作する場合は電気モータ駆動用サーボドライバの
制御線となる。また、スライド部９がエアシリンダによ
り上昇端の位置から下降動作を行う場合、ＣＰＵ１はポ
ートＰ３よりエアバルブへ下降指令を出力し、エアバル
ブはバルブを切り換えてエアシリンダ内の圧縮空気を排
気させ、エアシリンダに圧縮空気を供給しエアシリンダ
の下降動作を開始するが、エアシリンダ内の圧縮空気を
排気させるには時間がかかるため、ポートＰ３から下降
指令を出力した時点から実際にエアシリンダが下方へ動
き始めるまでには遅れ時間が有り、またスライド部９が
電気モータにより動作する場合についてもエアシリンダ
の場合と同様、ポートＰ３から下降指令を出力した時点
から実際にスライド部９が下方へ動き始めるまでには遅
れ時間が有る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of an automatic screw tightener 30 suitable for an embodiment of the present invention. The automatic screw tightening machine 30 includes a screw tightening head 20 for tightening the screw 16 on the work 17, a feeder 12 for supplying the screw 16 to the screw tightening head 20 via a screw pressure feeding hose 19, and the screw tightening head 20. Carrier unit 1 that moves in the X-axis direction
5X, the carrier portion 15Y for moving the work 17 in the Y-axis direction shown in the figure, and the carrier portions 15X, 15Y (hereinafter, the carrier portions 15X and 15Y are collectively referred to as the carrier portion 15) are positioned at predetermined teaching positions, and the screw tightening head is provided. It is composed of a control device 14 for operating 20. Screw tightening head 20
Is composed of a screw tightening driver 10 for tightening the screw 16 to the work 17, and a slide portion 9 for moving the screw tightening driver 10 up and down in the illustrated Z-axis direction by a built-in air cylinder or a motor. The carrier unit 15 includes the DC motors 3 for the carrier unit 15X and the carrier unit 15Y,
6 (hereinafter referred to as a motor) is moved by a rotation angle of the motors 3 and 6 via a ball screw directly connected to the motor. Reference numeral 13 denotes an operation unit including a keyboard, a display unit, and the like for teaching the screw tightening work to the automatic screw tightener 30 and setting the control operation. In FIG. 2, which shows a block diagram of the control device 14 of the automatic screw tightener 30, the parts having the same functions as those in FIG. 1 are denoted by the same reference numerals, and the control device 14 drives the motors 3 and 6, respectively. The motor drive circuits 2 and 5, a control line (hereinafter referred to as an SD signal) 31 for controlling driving and non-driving of the motors 3 and 6 by the motor drive circuits 2 and 5, and the motor 3 and
6, counters 4 and 7 that count pulses output from encoders 50 and 51 that are directly connected to 6, respectively, a driver drive unit 11 that drives a screw tightening driver 10, an operation unit 13 that inputs a work program, a ROM 29, RAM
28, I / O ports P1, P2, P3, P4, P5 and P10 and parallel I / O ports PD1, PD2 and PD
3 is a single chip, and is composed of a CPU 1 which executes a multi-process by time-sharing the control process of the motors 3, 6 and the screw tightening head 20. The port P5 of the CPU 1 is an output terminal that outputs a pressure feed command to the feeder 12, and the port P3 is a control line of an air valve that controls the supply / exhaust of compressed air to the air cylinder when the slide portion 9 operates by the air cylinder. When the slide portion 9 is operated by an electric motor, it serves as a control line for the electric motor driving servo driver. Further, when the slide portion 9 moves down from the position of the rising end by the air cylinder, the CPU 1 outputs a down command from the port P3 to the air valve, and the air valve switches the valve to exhaust the compressed air in the air cylinder. Compressed air is supplied to the cylinder to start the descent operation of the air cylinder, but it takes time to exhaust the compressed air in the air cylinder, so the air cylinder actually moves downward from the time when the descending command is output from port P3. There is a delay until the movement starts, and also when the slide portion 9 is operated by the electric motor, the slide portion 9 actually starts moving downward from the time when the descending command is output from the port P3, as in the case of the air cylinder. There is a delay before.
【００１０】上記のように構成された自動ねじ締め機３
０の動作について更に図３〜図７を参照しながら説明す
る。まず自動ねじ締め機３０を教示データに基づく自動
ねじ締め動作をさせる前に、キャリア部１５の加速度、
最高速度、減速度等の速度パターンと、ねじ締めヘッド
動作許可範囲となる第一のねじ締めヘッド動作許可範囲
Ｄと、図８に示すような例えば２個所のねじ締め作業を
行う場合の作業プログラム等を操作部１３より入力教示
する。ここでねじ締めヘッド動作許可範囲とは、キャリ
ア部１５が位置決め途上の状態においてねじ締めヘッド
２０を動作開始させても、位置決め完了時には正常なね
じ締め作業が可能なキャリア部１５の位置とねじ締め教
示位置との差の範囲であり、また第一のねじ締めヘッド
動作許可範囲Ｄとは、図４のＤに示すようにキャリア部
１５が位置決め完了前の位置決め途上の状態において、
キャリア部１５が所定のねじ締め教示位置に位置決め完
了した時にスライド部９が下方へ動き始めるような、前
述の遅れ時間を無くしたキャリア部１５の位置とねじ締
め教示位置との差の範囲である。なお、キャリア部１５
Ｘ、１５Ｙで位置決め時間が異なる場合は、夫々のキャ
リア部１５Ｘ、１５Ｙにねじ締めヘッド動作許可範囲を
設け、夫々が上記の動作許可範囲に入った状態に於てね
じ締めヘッド２０の動作を開始する。ＣＰＵ１はこれら
の教示データをポートＰＤ３より読み込みＲＡＭ２８に
記憶する。ここで２番目のねじ締め位置は、ワーク１７
のねじ下穴精度が悪い場合に対応させるもので、位置決
め点で位置の保持を解除しねじ締め作業を実行する。こ
の作業プログラムを実行するＣＰＵ１の処理の流れをフ
ローチャート図３に示す。以下図３を参照しながら説明
する。The automatic screw tightening machine 3 constructed as described above.
The operation of 0 will be further described with reference to FIGS. First, before performing the automatic screw tightening operation based on the teaching data by the automatic screw tightener 30, the acceleration of the carrier unit 15,
Speed patterns such as maximum speed and deceleration, a first screw tightening head operation allowable range D that is a screw tightening head operation allowable range, and a work program for performing screw tightening work at, for example, two places as shown in FIG. Etc. are input and taught from the operation unit 13. Here, the screw tightening head operation permission range means the position of the carrier portion 15 and the screw tightening position where normal screw tightening work can be performed when positioning is completed even if the screw tightening head 20 starts to operate while the carrier portion 15 is in the process of positioning. It is a range of difference from the taught position, and the first screw tightening head operation permission range D is, as shown in D of FIG. 4, in a state where the carrier portion 15 is in the middle of positioning before the positioning is completed.
This is a range of the difference between the position of the carrier portion 15 and the teaching position for screw tightening, in which the above-mentioned delay time is eliminated, so that the slide portion 9 starts to move downward when the positioning of the carrier portion 15 for the predetermined screw tightening teaching position is completed. . The carrier unit 15
When the positioning time is different between X and 15Y, a screw tightening head operation permission range is provided in each of the carrier portions 15X and 15Y, and the operation of the screw tightening head 20 is started in a state where each of them is in the above operation permission range. To do. The CPU 1 reads these teaching data from the port PD3 and stores it in the RAM 28. Here, the second screw tightening position is the work 17
It corresponds to the case where the accuracy of the screw prepared hole is poor, and the position is released at the positioning point and the screw tightening work is performed. FIG. 3 is a flow chart showing the processing flow of the CPU 1 that executes this work program. This will be described below with reference to FIG.
【００１１】ＣＰＵ１はまず作業プログラムのステップ
０を読み出し（１１２）、その作業内容を解読する（１
００）。いまステップ０の作業プログラムは移動ねじ締
めなので次の位置決め開始処理（１０１）へ移行し、絶
対座標で与えられた第１の教示位置へ向けてキャリア部
１５の移動を開始する。制御装置１４の位置決め処理
は、マルチ処理によりねじ締めヘッド２０とワーク１７
を移動する２つのキャリア部１５Ｘと１５Ｙを同時に制
御する。The CPU 1 first reads step 0 of the work program (112) and decodes the work contents (1
00). Since the work program in step 0 is tightening the moving screw, the process moves to the next positioning start process (101) to start moving the carrier unit 15 toward the first teaching position given in absolute coordinates. The positioning process of the control device 14 is performed by multi-process by the screw tightening head 20 and the work 17
The two carrier units 15X and 15Y moving in the same direction are simultaneously controlled.
【００１２】ここで一つの軸の位置決め制御方法につい
て図２を用いて説明すると、ＣＰＵ１には、所定の速度
パターンに従いかつキャリア部１５Ｘの位置と教示位置
との差つまり位置偏差が０になるように速度指令を出力
する位置制御系と位置制御系から出力された速度指令に
キャリア部１５Ｘの速度が合うように制御する速度制御
系のプログラムが組まれている。速度制御系では、速度
指令とキャリア部１５Ｘの速度の差から比例、積分、微
分の３要素からなるＰＩＤ演算を行って、パルス幅変調
方式によるＰＷＭパルスをＰ１より出力し、モータドラ
イブ回路２を介してモータ３を駆動し、カウンタ４がモ
ータ３に直結されたエンコーダ５０から出力されるエン
コーダパルスをカウントし、モータ３の回転角すなわち
キャリア部１５Ｘの位置を一定時間毎にＰＤ１より読み
取り、キャリア部１５Ｘの速度を算出し、キャリア部１
５Ｘの速度が速度指令に合うように制御する。また位置
制御系では、上記したように位置偏差が０になるように
速度指令を出力しキャリア部１５Ｘの位置制御を実行す
る。キャリア部１５Ｙの位置制御も上記と同様に同時に
時分割制御により実行され、キャリア部１５の位置決め
制御が行われる。A method for controlling the positioning of one axis will now be described with reference to FIG. 2. The CPU 1 follows the predetermined speed pattern and makes the difference between the position of the carrier portion 15X and the teaching position, that is, the position deviation zero. A position control system that outputs a speed command and a speed control system program that controls the speed of the carrier unit 15X to match the speed command output from the position control system are incorporated. In the speed control system, PID calculation consisting of three elements of proportional, integral, and differential is performed from the difference between the speed command and the speed of the carrier unit 15X, and a PWM pulse by the pulse width modulation method is output from P1 to drive the motor drive circuit 2. The motor 3 is driven through the counter 3, the counter 4 counts the encoder pulses output from the encoder 50 directly connected to the motor 3, the rotation angle of the motor 3, that is, the position of the carrier portion 15X is read from the PD 1 at regular time intervals, and The speed of the section 15X is calculated, and the carrier section 1
The speed of 5X is controlled to match the speed command. Further, the position control system outputs the speed command so that the position deviation becomes 0 as described above, and executes the position control of the carrier portion 15X. Similarly to the above, the position control of the carrier unit 15Y is also performed by the time division control, and the positioning control of the carrier unit 15 is performed.
【００１３】位置決め処理を開始したＣＰＵ１はキャリ
ア部１５の位置と教示位置との差が第一のねじ締めヘッ
ド動作許可範囲Ｄ内に入るまで待つ（１０２）。その位
置偏差が第一のねじ締めヘッド動作許可範囲Ｄ内に入る
と、ＣＰＵ１はポートＰ３、Ｐ４よりスライド部９を動
作させると共にねじ締めドライバ１０の回転及び下降を
開始し（１０３）、一方この状態に於てキャリア部１５
はまだ位置決め途上にある。次にＣＰＵ１は位置決め完
了後の位置の保持が必要であるか否かの判断を保持解除
フラグによって判断する（１０４）。いま保持解除フラ
グは設定されていないので次のねじ締め完了判断処理
（１０５）へ移行する。この時キャリア部１５の位置は
外力が加わっても教示位置に戻るような、いわゆるサー
ボロック動作により保持されたままの状態でねじ締め作
業が実行される。ねじ締め完了判断処理（１０５）では
ねじ締めドライバ１０が所定のトルクでワーク１７にね
じ１６を締め付けたか否か、ねじ浮きの有無等の判断処
理を実行する。またねじ締めドライバ１０が所定のトル
クでワーク１７にねじ１６を締め付けると、ドライバ駆
動部１１はねじ締めドライバ１０の回転を停止する。ね
じ締め作業が完了すると、ＣＰＵ１はポートＰ３よりス
ライド部９を動作させねじ締めドライバ１０の上昇を開
始する（１０６）。またポートＰ５よりフィーダ１２に
圧送指令を出力し、次のねじ締め作業に備えて、ねじ１
６は空気圧によりフィーダ１２からねじ圧送ホ−ス１９
を通してねじ締めヘッド２０へ供給される。The CPU 1 which has started the positioning process waits until the difference between the position of the carrier portion 15 and the teaching position falls within the first screw tightening head operation permission range D (102). When the positional deviation falls within the first screw tightening head operation permission range D, the CPU 1 operates the slide portion 9 from the ports P3 and P4 and starts rotating and lowering the screw tightening driver 10 (103). In the state, the carrier section 15
Is still in the process of being positioned. Next, the CPU 1 determines whether or not it is necessary to hold the position after the positioning is completed, based on the holding release flag (104). Since the holding release flag is not set now, the process proceeds to the next screw tightening completion determination process (105). At this time, the screw tightening operation is performed in a state where the carrier portion 15 returns to the teaching position even if an external force is applied, that is, the carrier portion 15 is held by a so-called servo lock operation. In the screw tightening completion determination process (105), a process for determining whether or not the screw tightening driver 10 has tightened the screw 16 on the work 17 with a predetermined torque and whether or not the screw is floating. Further, when the screw tightening driver 10 tightens the screw 16 to the work 17 with a predetermined torque, the driver driving unit 11 stops the rotation of the screw tightening driver 10. When the screw tightening work is completed, the CPU 1 operates the slide portion 9 from the port P3 to start the raising of the screw tightening driver 10 (106). In addition, a pressure feed command is output from the port P5 to the feeder 12 so that the screw 1 is ready for the next screw tightening work.
6 is a screw feed hose 19 from the feeder 12 by air pressure
Is supplied to the screw tightening head 20 through.
【００１４】上記した制御方法によると、キャリア部１
５の位置偏差と各処理のタイミングチャートを示す図４
に於て、縦軸は位置偏差、横軸は時間を表示したもので
あり、従来の自動ねじ締め機のねじ締めタイミングチャ
ートＡに比べ、第一のねじ締めヘッド動作許可範囲Ｄに
よるねじ締めタイミングチャートＢに示すようにＴ１時
間分、ねじ締め作業時間を短縮でき、ｎ本締めのワーク
の場合１ワーク当たりｎ×Ｔ１時間のねじ締め作業時間
が短縮できる。According to the above control method, the carrier unit 1
4 shows a positional deviation of No. 5 and a timing chart of each processing.
The vertical axis represents position deviation and the horizontal axis represents time. Compared to the screw tightening timing chart A of the conventional automatic screw tightening machine, the screw tightening timing according to the first screw tightening head operation permission range D is shown. As shown in the chart B, the screw tightening work time can be shortened by T1 hours, and in the case of a work of n main tightening, the screw tightening work time can be shortened by n × T1 hour per work.
【００１５】上記のようにステップ０の第１のねじ締め
作業が終了するとＣＰＵ１はステップを更新し（１０
７）、次ステップであるステップ１の保持解除を読み出
し（１１２）、処理（１００）の判定で処理（１０８）
へ移行し、ステップの内容は保持解除なので保持解除フ
ラグを設定する（１０９）。ＣＰＵ１は再びステップ更
新処理を実行し（１０７）、次ステップであるステップ
２の移動ねじ締めを読み出し（１１２）、ステップ内容
を解読して（１００）位置決め開始へ移行し（１０
１）、第２のねじ締め位置へ向けてキャリア部１５の移
動を開始する。キャリア部１５の位置と教示位置との差
が第一のねじ締めヘッド動作許可範囲Ｄ内に入ると（１
０２）、ねじ締めドライバ１０の回転及び下降を開始す
る（１０３）。ステップ１の処理で保持解除フラグは設
定されているため処理（１１０）へ移行し、キャリア部
１５の位置が所定の許容停止精度Ｆ内に入ると位置決め
処理を終了し、ＣＰＵ１はＳＤ信号３１を論理”Ｌｏ”
状態から論理”Ｈｉ”状態に反転し、キャリア部１５の
位置の保持を解除する処理を行う（１１１）。キャリア
部１５の位置の保持を解除するその他の方法としては、
リレ−等を用いてモータ３、６へ流す電流を遮断する処
理等があるが、本実施例に於ては、モータドライブ回路
２、５において、図７に示すように電界効果トランジス
タ（以下ＦＥＴという）Ｑ１からＱ４の４つのＦＥＴを
用いてモータの正転及び逆転を行うコンデンサ回生方式
によるモータ３、６のドライブ回路において、ＳＤ信号
３１を論理”Ｈｉ”状態にすることにより、前段のＣＭ
ＯＳロジック素子ＩＣ１、ＩＣ２、ＩＣ３、ＩＣ４の出
力をハイインピ−ダンス状態にして、ＦＥＴＱ１、Ｑ
２、Ｑ３、Ｑ４の４素子とも全てオフさせモータ３、６
へ流す電流を遮断する例を示す。When the first screw tightening work of step 0 is completed as described above, the CPU 1 updates the step (10
7), read out the holding release of the next step, step 1 (112), and process (108) by the determination of process (100).
Since the contents of the step are released, the holding release flag is set (109). The CPU 1 executes the step update process again (107), reads the moving screw tightening of the next step, Step 2, (112), decodes the step content (100), and shifts to the positioning start (10).
1), the movement of the carrier portion 15 is started toward the second screw tightening position. When the difference between the position of the carrier portion 15 and the taught position falls within the first screw tightening head operation permission range D (1
02), the screw tightening driver 10 starts to rotate and descend (103). Since the holding release flag is set in the process of step 1, the process proceeds to process (110), and when the position of the carrier unit 15 is within the predetermined permissible stop accuracy F, the positioning process ends, and the CPU 1 outputs the SD signal 31. Logical "Lo"
The state is inverted to the logical "Hi" state, and the process of releasing the holding of the position of the carrier portion 15 is performed (111). As another method of releasing the holding of the position of the carrier portion 15,
Although there is a process of cutting off the current flowing to the motors 3 and 6 by using a relay or the like, in this embodiment, in the motor drive circuits 2 and 5, as shown in FIG. In the drive circuit of the motors 3 and 6 of the condenser regenerative system that performs normal rotation and reverse rotation of the motor using the four FETs Q1 to Q4, the SD signal 31 is set to the logical "Hi" state, thereby
The outputs of the OS logic elements IC1, IC2, IC3, IC4 are set to the high impedance state, and the FETs Q1, Q
Turn off all the four elements of 2, Q3, and Q4.
An example of cutting off the current flowing to is shown.
【００１６】ここでモータドライブ回路２について図７
を用いて説明すると、モータドライブ回路２は、ＦＥＴ
Ｑ１、ＦＥＴＱ２、ＦＥＴＱ３およびＦＥＴＱ４と、こ
れらＦＥＴＱ１〜Ｑ４をＨ状に回路を組み、ＦＥＴＱ１
とＦＥＴＱ２の接続点とＦＥＴＱ３とＦＥＴＱ４の接続
点にモータ３を接続してある。ＦＥＴＱ１〜Ｑ４のゲ−
ト部には、ＦＥＴＱ１をオンさせるための電荷を供給す
るコンデンサＣ１と、ＦＥＴＱ３をオンさせるための電
荷を供給するコンデンサＣ２と、コンデンサＣ１に蓄え
られた電荷が電源＋７Ｖ側へ逆流するのを防止するダイ
オ−ドＤ１と、コンデンサＣ２に蓄えられた電荷が電源
＋７Ｖ側へ逆流するのを防止するダイオ−ドＤ２と、Ｆ
ＥＴＱ１をオン・オフさせＦＥＴＱ１のソ−ス端子と同
電位のグランドレベルを持つホトカプラＰＨ１と、ＦＥ
ＴＱ３をオン・オフさせＦＥＴＱ３のソ−ス端子と同電
位のグランドレベルを持つホトカプラＰＨ２と、ホトカ
プラＰＨ１をオン・オフするＩＣ１と、ホトカプラＰＨ
２をオン・オフするＩＣ３が設けられている。更にＦＥ
ＴＱ２をオン・オフするＩＣ２と、ＦＥＴＱ４をオン・
オフするＩＣ４と、デッドタイム回路２７が設けられ、
デッドタイム回路２７からは、ＩＣ１、ＩＣ４にはパル
ス幅制御信号ＰＷＭ１と、ＩＣ２、ＩＣ３にはパルス幅
制御信号ＰＷＭ２が出力される。デッドタイム回路２７
はＣＰＵ１のＰ１出力端子より出力されたＰＷＭパルス
からパルス幅制御信号ＰＷＭ１、ＰＷＭ２に変換し、Ｆ
ＥＴＱ１とＦＥＴＱ２あるいはＦＥＴＱ３とＦＥＴＱ４
が同時にオンするのを防止する。ＣＰＵ１のＰ１０出力
端子からは、ＩＣ１、ＩＣ２、ＩＣ３およびＩＣ４の出
力端子を、論理レベルを出力するイネーブル状態あるい
はハイインピーダンス状態に制御するＳＤ信号３１が出
力されている。ＳＤ信号３１が論理”Ｈｉ”状態になる
と、ＦＥＴＱ１〜Ｑ４は全てオフし、モータ３による位
置の保持は解除される。更にＦＥＴＱ１、Ｑ２、Ｑ３、
Ｑ４のゲートには夫々ゲート電流制限用の抵抗器５４、
５５、５６、５７が接続され、下アームのＦＥＴＱ２、
Ｑ４のゲート・ソース間にはゲート電荷放電用の抵抗器
５８、５９が並列に接続されている。５２、５３は夫々
ホトカプラＰＨ１、ＰＨ２の発光素子に電源＋５Ｖから
流れる電流を制限する抵抗器であり、６０は電源＋３８
ＶとＧＮＤの間に設けられたモータ３の電流帰還用コン
デンサであり、６１はＨブリッジ回路に流れる電流の立
上りを抑制するチョークコイル、６２はチョークコイル
６１のフライバック用ダイオードである。なお、ＦＥＴ
Ｑ１、Ｑ２、Ｑ３、Ｑ４には図示のように逆並列に電流
還流用のダイオードが設けられている。また、電源＋５
Ｖ、＋７Ｖは共にＧＮＤで示す点を基準電位としてい
る。なお、モータドライブ回路５はモータドライブ回路
２と同一の構成になる。Here, the motor drive circuit 2 is shown in FIG.
The motor drive circuit 2 is a FET
Q1, FETQ2, FETQ3 and FETQ4, and these FETQ1 to Q4 are assembled into an H-shaped circuit, and FETQ1
The motor 3 is connected to the connection point of the FET Q2 and the connection point of the FET Q3 and the FET Q4. FETs Q1 to Q4
A capacitor C1 for supplying electric charge for turning on the FET Q1, a capacitor C2 for supplying electric charge for turning on the FET Q3, and a charge stored in the capacitor C1 are prevented from flowing back to the power supply + 7V side in the gate portion. And a diode D2 for preventing the electric charge accumulated in the capacitor C2 from flowing back to the power supply + 7V side.
ETQ1 is turned on / off, and a photocoupler PH1 having a ground level of the same potential as the source terminal of FETQ1 and FE
A photocoupler PH2 having a ground level of the same potential as the source terminal of the FET Q3 for turning on / off the TQ3, an IC1 for turning on / off the photocoupler PH1, and a photocoupler PH.
An IC 3 for turning on / off 2 is provided. Further FE
Turn on and off IC2 that turns on and off TQ2, and turn on and off FETQ4
An IC4 to turn off and a dead time circuit 27 are provided,
The dead time circuit 27 outputs a pulse width control signal PWM1 to IC1 and IC4 and a pulse width control signal PWM2 to IC2 and IC3. Dead time circuit 27
Converts the PWM pulse output from the P1 output terminal of the CPU1 into pulse width control signals PWM1 and PWM2, and
ETQ1 and FETQ2 or FETQ3 and FETQ4
Prevent them from turning on at the same time. An SD signal 31 for controlling the output terminals of IC1, IC2, IC3 and IC4 to an enable state or a high impedance state for outputting a logic level is output from the P10 output terminal of the CPU1. When the SD signal 31 becomes the logic "Hi" state, all the FETs Q1 to Q4 are turned off, and the holding of the position by the motor 3 is released. In addition, FETs Q1, Q2, Q3,
A resistor 54 for limiting the gate current is provided at the gate of Q4,
55, 56, 57 are connected, and FET Q2 of the lower arm,
Resistors 58 and 59 for discharging the gate charge are connected in parallel between the gate and the source of Q4. Reference numerals 52 and 53 are resistors for limiting the current flowing from the power source + 5V to the light emitting elements of the photocouplers PH1 and PH2, respectively, and 60 is the power source +38.
Reference numeral 61 is a current feedback capacitor of the motor 3 provided between V and GND, 61 is a choke coil that suppresses the rise of the current flowing in the H bridge circuit, and 62 is a flyback diode of the choke coil 61. In addition, FET
As shown, Q1, Q2, Q3, and Q4 are provided with diodes for current circulation in antiparallel. Also, power supply +5
For both V and + 7V, the point indicated by GND is used as the reference potential. The motor drive circuit 5 has the same configuration as the motor drive circuit 2.
【００１７】上記のように構成されたモータドライブ回
路２における上アームのＦＥＴＱ１、Ｑ３を駆動させモ
ータ３に電流を流す方法について説明する。ＣＰＵ１の
Ｐ１出力端子から出力されたＰＷＭパルスは同一アーム
のＦＥＴＱ１とＱ２或いはＦＥＴＱ３とＱ４が同時にオ
ンするのを防止するデッドタイム回路２７を通って２本
のパルス幅制御信号ＰＷＭ１、ＰＷＭ２を作る。パルス
幅制御信号ＰＷＭ１とＰＷＭ２は一周期のうち、デッド
タイム期間は論理”Ｌｏ”状態であり、その他の期間は
互いに反対の論理を取る。いま、ＦＥＴＱ１、Ｑ４のオ
ン・オフに関与する信号ＰＷＭ１が論理”Ｈｉ”状態
で、ＦＥＴＱ２、Ｑ３のオン・オフに関与する信号ＰＷ
Ｍ２が論理”Ｌｏ”状態で、ＳＤ信号３１が論理”Ｌ
ｏ”状態の場合は、ＩＣ４は論理”Ｈｉ”状態を出力し
ＦＥＴＱ４をオンさせ、ダイオードＤ２からコンデンサ
Ｃ２を通りＦＥＴＱ４へ流れる電流はコンデンサＣ２を
蓄電する。続いて信号ＰＷＭ１が論理”Ｌｏ”状態で信
号ＰＷＭ２が論理”Ｈｉ”状態になると、ＩＣ２は論
理”Ｈｉ”状態を出力しＦＥＴＱ２をオンさせ、ダイオ
ードＤ１からコンデンサＣ１を通りＦＥＴＱ２へ流れる
電流はコンデンサＣ１を蓄電する。最初のＰＷＭパルス
一周期の後、蓄電されたコンデンサＣ１、Ｃ２の電荷を
ホトカプラＰＨ１、ＰＨ２を使ってＦＥＴＱ１、Ｑ３を
オンさせるが、その動作は、信号ＰＷＭ１が論理”Ｈ
ｉ”状態で信号ＰＷＭ２が論理”Ｌｏ”状態の時、ＩＣ
４は論理”Ｈｉ”状態を出力しＦＥＴＱ４をオンさせ、
ＩＣ１は論理”Ｌｏ”状態を出力しホトカプラＰＨ１は
オンしコンデンサＣ１に蓄えられた電荷をＦＥＴＱ１へ
供給してＦＥＴＱ１をオンさせ、またＩＣ２は論理”Ｌ
ｏ”状態を出力しＦＥＴＱ２をオフさせ、ＩＣ３は論
理”Ｈｉ”状態を出力しホトカプラＰＨ２はオフのため
ＦＥＴＱ３はオフする。この時モータ３へ流れる電流は
図示のｉ１のル−トで流れ、さらに信号ＰＷＭ１が論
理”Ｌｏ”状態で信号ＰＷＭ２が論理”Ｈｉ”状態に反
転すると、前記各素子は逆の動作を行ってＦＥＴＱ２、
Ｑ３がオンしＦＥＴＱ１、Ｑ４がオフし、電源＋７Ｖか
らダイオードＤ１、コンデンサＣ１を通りＦＥＴＱ２へ
流れる電流はコンデンサＣ１を蓄電し、同時にＦＥＴＱ
２とＦＥＴＱ３の電流還流用ダイオードを流れる回生電
流ｉ２と、電源＋３８ＶからＦＥＴＱ３とＦＥＴＱ２を
流れる電源電流ｉ３がモータ３に流れる。この動作を繰
り返して行うことにより、ＦＥＴＱ１とＦＥＴＱ４がオ
ンでＦＥＴＱ２とＦＥＴＱ３がオフの場合は回生電流ｉ
４と電源電流ｉ１が流れ、またＦＥＴＱ２とＦＥＴＱ３
がオンでＦＥＴＱ１とＦＥＴＱ４がオフの場合は回生電
流ｉ２と電源電流ｉ３が流れ、モータ３を駆動する。な
お、モータドライブ回路５はモータドライブ回路２と同
様に動作する。A method of driving the upper arm FETs Q1 and Q3 in the motor drive circuit 2 configured as described above to supply a current to the motor 3 will be described. The PWM pulse output from the P1 output terminal of the CPU 1 passes through the dead time circuit 27 that prevents the FETs Q1 and Q2 or the FETs Q3 and Q4 of the same arm from being turned on at the same time to generate two pulse width control signals PWM1 and PWM2. The pulse width control signals PWM1 and PWM2 are in the logic "Lo" state during the dead time period in one cycle, and have the opposite logic during the other periods. Now, when the signal PWM1 involved in turning on / off the FETs Q1 and Q4 is in the logic "Hi" state, the signal PW involved in turning on / off the FETs Q2 and Q3.
When the M2 is in the logic "Lo" state, the SD signal 31 is in the logic "L"
In the case of the "o" state, the IC4 outputs the logic "Hi" state to turn on the FET Q4, and the current flowing from the diode D2 through the capacitor C2 to the FET Q4 stores the capacitor C2. Subsequently, the signal PWM1 is in the logic "Lo" state. Then, when the signal PWM2 becomes the logic "Hi" state, the IC2 outputs the logic "Hi" state to turn on the FET Q2, and the current flowing from the diode D1 through the capacitor C1 to the FET Q2 stores the capacitor C1. After the cycle, the electric charges of the stored capacitors C1 and C2 are turned on by using the photocouplers PH1 and PH2 to turn on the FETs Q1 and Q3.
When the signal PWM2 is in the logic "Lo" state in the i "state, the IC
4 outputs a logic "Hi" state to turn on FET Q4,
IC1 outputs the logic "Lo" state, the photocoupler PH1 is turned on, the charge accumulated in the capacitor C1 is supplied to the FET Q1 to turn on the FET Q1, and the IC2 is logic "L".
FET3 is output, the FETQ2 is turned off, the IC3 outputs the logic "Hi" state, and the photocoupler PH2 is turned off, so the FETQ3 is turned off. At this time, the current flowing to the motor 3 flows in the route of i1 shown in the figure, Furthermore, when the signal PWM1 is inverted to the logical "Lo" state and the signal PWM2 is inverted to the logical "Hi" state, the above-mentioned elements perform the opposite operations to the FET Q2,
Q3 is turned on, FETs Q1 and Q4 are turned off, and the current flowing from the power source + 7V through the diode D1 and the capacitor C1 to the FET Q2 is stored in the capacitor C1.
2 and the regenerative current i2 flowing through the current return diode of the FET Q3, and the power supply current i3 flowing through the FET Q3 and the FET Q2 from the power supply +38 V flows to the motor 3. By repeating this operation, when the FETQ1 and FETQ4 are on and the FETQ2 and FETQ3 are off, the regenerative current i
4 and power supply current i1 flow, and FETQ2 and FETQ3
When is on and FETQ1 and FETQ4 are off, regenerative current i2 and power supply current i3 flow to drive the motor 3. The motor drive circuit 5 operates similarly to the motor drive circuit 2.
【００１８】上記の方法でキャリア部１５の位置保持を
解除した時のねじ締め過程について説明する。図６に示
すように殆どのねじ１６のねじ先端部１６ａはねじ締め
やすくするため円錐状になっている。ねじ締めドライバ
１０がそのまま回転及び下降を続けるとワーク１７のね
じ下穴中心とビット２１の中心にズレ量ａがあっても互
いの中心を合わせようとする力が生まれ、ねじ締めドラ
イバ１０およびワーク１７を固定したキャリア部１５が
ワーク１７のねじ下穴中心とビット２１の中心が合う方
向へ倣い、正常なねじ締め作業が行われる。A screw tightening process when the position holding of the carrier portion 15 is released by the above method will be described. As shown in FIG. 6, most of the screw tips 16a of the screws 16 have a conical shape for easy screw tightening. If the screw tightening driver 10 continues to rotate and descend as it is, even if there is a deviation amount a between the center of the screw hole of the work 17 and the center of the bit 21, a force is generated to match the centers of the screw tightening driver 10 and the work. The carrier portion 15 to which 17 is fixed follows the direction in which the center of the screw hole of the work 17 and the center of the bit 21 are aligned, and a normal screw tightening operation is performed.
【００１９】処理（１０５）においてねじ締め作業が完
了すると、ＣＰＵ１はポートＰ３よりスライド部９を動
作させねじ締めドライバ１０の上昇を開始し（１０
６）、またポートＰ５よりフィーダ１２に圧送指令を出
力し、次のねじ締め作業に備えてねじ１６をねじ締めヘ
ッド２０へ供給し、ステップ更新を行って（１０７）、
次ステップは作業プログラムが入力されていないことか
らワーク１７のねじ締め作業が終了したことを認識し、
ワーク１７を搬出及び搬入する待機位置へ移動し、ねじ
締め作業を終了する。When the screw tightening work is completed in the process (105), the CPU 1 operates the slide portion 9 from the port P3 and starts the screw tightening driver 10 to rise (10
6) Also, a pressure feed command is output from the port P5 to the feeder 12, the screw 16 is supplied to the screw tightening head 20 in preparation for the next screw tightening work, and step updating is performed (107).
The next step is to recognize that the work 17 screw tightening work has been completed because no work program has been entered.
The work 17 is moved to the standby position where it is carried out and carried in, and the screw tightening work is completed.
【００２０】上記したねじ締めヘッド２０の動作開始条
件は、キャリア部１５の位置と教示位置との差が第一の
ねじ締めヘッド動作許可範囲Ｄであったが、更にねじ締
め作業時間を短縮するためねじ締めヘッド動作許可範囲
を拡げ、第二のねじ締めヘッド動作許可範囲Ｅを設定す
る。ここでねじ締めヘッド動作許可範囲となる第二のね
じ締めヘッド動作許可範囲Ｅとは、図４のＥに示すよう
にキャリア部１５が位置決め完了前の位置決め途上の状
態において、ねじ締めヘッド２０を動作開始させてもね
じ締めヘッド２０とワーク１７が衝突せず、かつねじ締
めヘッド２０がワーク１７にねじ締め動作を実行する時
には、図４に示す許容停止精度Ｆ内に位置決めが完了す
るような、ねじ締めヘッド２０を動作開始させる時のキ
ャリア部１５の位置と教示位置との差の範囲であり、例
えばキャリア部１５の位置が許容停止精度Ｆ内になった
時、図６に示すようにねじ締めドライバのビット２１先
端部で保持されたねじ１６の先端部１６ａがワーク面１
７ａよりも少し上方にあり当接しないように設定すれば
良い。なお、キャリア部１５Ｘ、１５Ｙで位置決め時間
が異なる場合は、それぞれのキャリア部１５Ｘ、１５Ｙ
にねじ締めヘッド動作許可範囲を設け、それぞれが上記
の動作許可範囲Ｅに入った状態においてねじ締めヘッド
２０の動作を開始する。この第二のねじ締めヘッド動作
許可範囲Ｅは第一のねじ締めヘッド動作許可範囲Ｄと同
様、操作部１３によりＣＰＵ１のＲＡＭ２８上に記憶設
定される範囲を示す数値データが書き換えられるように
なっている。この第二のねじ締めヘッド動作許可範囲Ｅ
を用いて前述した制御方法でねじ締め作業を実行する
と、ねじ締めヘッド２０の下端部の軌跡を例示する図５
において、同図において図１、図６と同一の機能の部分
には同一に番号が符してあり、ねじ締めヘッド下端部は
図５に示すような軌跡が描かれ、図４のＣに示すように
第一のねじ締めヘッド動作許可範囲Ｄを用いた場合に比
べ、（Ｔ２−Ｔ１）時間分ねじ締め作業を短縮できる。The operation start condition of the screw tightening head 20 is that the difference between the position of the carrier portion 15 and the teaching position is the first screw tightening head operation permission range D, but the screw tightening work time is further shortened. Therefore, the screw tightening head operation permission range is expanded and the second screw tightening head operation permission range E is set. Here, the second screw tightening head operation allowable range E, which is the screw tightening head operation allowable range, refers to the screw tightening head 20 when the carrier portion 15 is in the middle of positioning before completion of positioning as shown in E of FIG. Even when the operation is started, the screw tightening head 20 does not collide with the work 17, and when the screw tightening head 20 performs the screw tightening operation on the work 17, the positioning is completed within the allowable stop accuracy F shown in FIG. 6 is a range of the difference between the position of the carrier portion 15 and the teaching position when the screw tightening head 20 starts to operate. For example, when the position of the carrier portion 15 is within the allowable stop accuracy F, as shown in FIG. The tip 16a of the screw 16 held by the tip of the bit 21 of the screw tightening driver is the work surface 1
It may be set a little above 7a so as not to abut. When the positioning times of the carrier parts 15X and 15Y are different, the respective carrier parts 15X and 15Y are arranged.
The screw tightening head operation permission range is provided in each of them, and the operation of the screw tightening head 20 is started in a state where each of them enters the above operation permission range E. As with the first screw tightening head operation allowance range D, the second screw tightening head operation allowance range E can be rewritten by numerical data indicating the range stored and set in the RAM 28 of the CPU 1 by the operation unit 13. There is. This second screw tightening head movement permission range E
5 illustrates the locus of the lower end portion of the screw tightening head 20 when the screw tightening work is executed by the above-described control method using FIG.
In the figure, the parts having the same functions as those in FIGS. 1 and 6 are designated by the same numerals, and the locus as shown in FIG. 5 is drawn at the lower end of the screw tightening head, and shown in C of FIG. As described above, as compared with the case where the first screw tightening head operation permission range D is used, the screw tightening work can be shortened by (T2-T1) time.
【００２１】更に上記したねじ締めヘッド２０の動作開
始条件は、キャリア部１５の位置と教示位置との差がね
じ締めヘッド動作許可範囲内に入るとねじ締めヘッド２
０を動作させるものであったが、キャリア部１５が位置
決め途上の状態においてねじ締めヘッド２０を動作開始
させても、位置決め完了時には正常なねじ締め作業がで
きるような、キャリア部１５が教示位置に停止するまで
の時間であるねじ締めヘッド動作許可時間を操作部１３
より設定する。ＣＰＵ１は、キャリア部１５が所定の教
示位置に停止するまでの時間ｔをサンプリング周期毎に
計算し、この時間ｔがねじ締めヘッド動作許可時間以内
になった時ねじ締めヘッド２０を動作させる。この時間
ｔの計算方法は、キャリア部１５の位置と教示位置との
差Ｌと、キャリア部１５の速度ｖと、所定の速度パター
ンの所定減速度α（α＜０）から周知の式であるＬ＝ｖ
ｔ＋αｔ2／２を用いて計算するが、この２次方程式か
ら得られる二つのｔの解のうち、正であるものを用い
る。上記したようにねじ締めヘッド２０の動作開始条件
を、ねじ締めヘッド動作許可範囲ではなくねじ締めヘッ
ド動作許可時間とし、前述した制御方法によりねじ締め
作業時間を短縮できることは明らかである。またねじ締
めヘッド動作許可時間は、ねじ締めヘッド動作許可範囲
と同様、操作部１３より設定変更可能である。Further, the operation start condition of the screw tightening head 20 described above is such that when the difference between the position of the carrier portion 15 and the teaching position falls within the screw tightening head operation permission range.
However, even if the screw tightening head 20 is started while the carrier unit 15 is in the process of positioning, the carrier unit 15 is set to the teaching position so that the screw tightening work can be performed normally when the positioning is completed. The operation time of the screw tightening head operation permission time, which is the time until it stops
Set more. The CPU 1 calculates the time t until the carrier unit 15 stops at a predetermined teaching position for each sampling cycle, and operates the screw tightening head 20 when this time t falls within the screw tightening head operation permission time. The calculation method of this time t is a well-known formula from the difference L between the position of the carrier part 15 and the teaching position, the speed v of the carrier part 15, and a predetermined deceleration α (α <0) of a predetermined speed pattern. L = v
The calculation is performed using t + αt 2/2, and the positive one of the two solutions of t obtained from this quadratic equation is used. As described above, it is apparent that the operation start condition of the screw tightening head 20 is set to the screw tightening head operation allowance time instead of the screw tightening head operation allowance range, and the screw tightening work time can be shortened by the control method described above. Further, the screw tightening head operation permission time can be set and changed by the operation unit 13 like the screw tightening head operation permission range.
【００２２】上記した制御方法では、キャリア部１５が
位置決め途上の状態においてスライド部９を下方へ動作
させる場合について説明したが、逆にねじ締め作業完了
後、スライド部９が上方へ移動中に次のねじ締め教示位
置へ向けてキャリア部１５を移動させる制御方法につい
て説明する。まず、スライド部９が上昇時、ねじ締めヘ
ッド２０の下端部がワーク１７に衝突しないような位置
を検知するセンサをねじ締めヘッド２０に設ける。上記
構成において、ＣＰＵ１は、例えば電動ドライバのトル
クアップ信号を検知してねじ締め作業が完了するとポー
トＰ３よりスライド部９を上方へ移動開始させる。ねじ
締めヘッド２０に設けたセンサはねじ締めヘッド２０の
下端部がワーク１７に衝突しない位置までスライド部９
が上昇するとＯＮし、ＣＰＵ１は、スライド部９がねじ
締めヘッド２０下端部とワーク１７は衝突しない位置ま
で上昇したことを認識し、次のねじ締め教示位置へ向け
てキャリア部１５を移動させる。または、上記のように
ねじ締めヘッド２０の下端部がワーク１７に衝突しない
ような位置を検出するセンサを設けず、電動ドライバの
トルクアップ信号を検知した後、タイマ手段によりスラ
イド部９が上昇中に次のねじ締め教示位置へ向けてキャ
リア１５を移動させることによっても良い。上記制御方
法によると、ねじ締め作業完了後、スライド部９を上端
まで移動させずにキャリア部１５を次のねじ締め教示位
置へ向けて移動させることができるため、ねじ締め作業
全体の作業時間を短縮できる。In the control method described above, the case has been described in which the slide portion 9 is moved downward while the carrier portion 15 is in the course of positioning, but conversely, after the screwing work is completed, the slide portion 9 is moved upward while moving. A control method for moving the carrier portion 15 toward the screw tightening teaching position will be described. First, the screw tightening head 20 is provided with a sensor that detects a position where the lower end of the screw tightening head 20 does not collide with the work 17 when the slide portion 9 rises. In the above structure, the CPU 1 starts moving the slide portion 9 upward from the port P3 when the screw tightening work is completed by detecting a torque-up signal from the electric driver, for example. The sensor provided on the screw tightening head 20 slides to a position where the lower end of the screw tightening head 20 does not collide with the work 17.
Is turned on, the CPU 1 recognizes that the slide portion 9 has risen to a position where the lower end of the screw tightening head 20 and the work 17 do not collide, and moves the carrier part 15 toward the next screw tightening teaching position. Alternatively, as described above, the sensor for detecting the position where the lower end of the screw tightening head 20 does not collide with the work 17 is not provided, and after the torque-up signal of the electric driver is detected, the slide portion 9 is moving upward by the timer means. Alternatively, the carrier 15 may be moved toward the next screw tightening teaching position. According to the above control method, after the screw tightening work is completed, the carrier portion 15 can be moved to the next screw tightening teaching position without moving the slide portion 9 to the upper end, so that the work time of the entire screw tightening work is reduced. Can be shortened.
【００２３】なお、図９の作業プログラム例に示すよう
に、ステップ０の第一の移動ねじ締め作業とステップ２
の第二の移動ねじ締め作業の間に、キャリア部１５の移
動によるねじ締めヘッド２０とワーク１７の衝突を回避
するため、ステップ１にパスポイント移動をプログラム
することがあるが、この場合にも、第一またいは第二の
ねじ締めヘッド動作許可範囲Ｄ、Ｅの設定に従って、ね
じ締めヘッド２０及びワーク１７をキャリア部１５によ
り移動させると、図４に示す許容停止精度Ｆの位置決め
をする必要がないため、パスポイントの位置決め完了が
短時間で実行され、ねじ締め作業全体の高速化が行え
る。As shown in the example of the work program of FIG. 9, the first moving screw tightening work of step 0 and step 2
In order to avoid the collision between the screw tightening head 20 and the work 17 due to the movement of the carrier portion 15 during the second moving screw tightening work of No. 1, the pass point movement may be programmed in step 1. When the screw tightening head 20 and the work 17 are moved by the carrier unit 15 according to the setting of the first or second screw tightening head operation permission ranges D and E, it is necessary to perform positioning with the allowable stop accuracy F shown in FIG. Since the positioning of the pass point is completed in a short time, the entire screw tightening work can be speeded up.
【００２４】[0024]
【発明の効果】本発明によれば、自動ねじ締め機にキャ
リア部を所定の教示位置へ位置決めする以前にねじ締め
ヘッドを動作させる制御装置を備えたので、１本のねじ
締め作業につきねじ締めヘッド動作開始から位置決めが
完了するまでの時間分ねじ締め作業時間を短縮すること
ができる。According to the present invention, since the automatic screw tightening machine is provided with the control device for operating the screw tightening head before positioning the carrier portion at the predetermined teaching position, the screw tightening is performed for each screw tightening operation. The screw tightening work time can be shortened by the time from the start of the head operation until the positioning is completed.
【００２５】また本発明によれば、自動ねじ締め機にキ
ャリア部の位置保持を解除させる機能を持たせたので、
ビットの中心とワークのねじ下穴の中心がずれている場
合でも正常なねじ締めを行い、ねじ締め作業能率を向上
させることができる。Further, according to the present invention, since the automatic screw fastening machine is provided with the function of releasing the position holding of the carrier portion,
Even if the center of the bit and the center of the screw hole of the work are misaligned, the screw can be tightened normally and the screw tightening work efficiency can be improved.
【図面の簡単な説明】[Brief description of drawings]
【図１】本発明の一実施例を示す自動ねじ締め機の斜視
図。FIG. 1 is a perspective view of an automatic screw tightening machine showing an embodiment of the present invention.
【図２】自動ねじ締め機の制御装置のブロック図。FIG. 2 is a block diagram of a control device of the automatic screw tightening machine.
【図３】ＣＰＵの処理を表すフローチャート。FIG. 3 is a flowchart showing processing of a CPU.
【図４】キャリア部の位置偏差と各処理のタイミングチ
ャート。FIG. 4 is a timing chart of position deviation of the carrier unit and each processing.
【図５】ねじ締めヘッド下端部の軌跡を例示する側面
図。FIG. 5 is a side view illustrating the locus of the lower end portion of the screw tightening head.
【図６】ビット中心とワークのねじ下穴中心がずれてい
る場合を示す側面図。FIG. 6 is a side view showing a case where the center of the bit and the center of the screw hole of the work are deviated.
【図７】モータドライブ回路図。FIG. 7 is a motor drive circuit diagram.
【図８】作業プログラムを示す図。FIG. 8 is a diagram showing a work program.
【図９】他の作業プログラムを示す図。FIG. 9 is a diagram showing another work program.
１はＣＰＵ、９はスライド部、１０はねじ締めドライ
バ、１３は操作部、１４は制御装置、１５はキャリア
部、１６はねじ、１７はワーク、２０はねじ締めヘッ
ド、２１はビット、３０は自動ねじ締め機、３１はＳＤ
信号である。1 is a CPU, 9 is a slide part, 10 is a screw tightening driver, 13 is an operating part, 14 is a controller, 15 is a carrier part, 16 is a screw, 17 is a work, 20 is a screw tightening head, 21 is a bit, 30 is Automatic screw tightener, 31 is SD
It is a signal.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 干場 英城 茨城県勝田市武田1060番地 日立工機株式 会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiba Hagi Castle 1060 Takeda, Katsuta City, Ibaraki Prefecture Hitachi Koki Co., Ltd.
Claims (8)
と、前記ねじ締めヘッドを前記ワークのねじ締め位置に
移動するキャリア部と、前記キャリア部を所定のねじ締
め教示位置へ位置決めする以前に前記ねじ締めヘッドを
動作させる制御装置を備えたことを特徴とする自動ねじ
締め機。1. A screw tightening head for tightening a screw to a work, a carrier part for moving the screw tightening head to a screw tightening position of the work, and the screw before positioning the carrier part to a predetermined screw tightening teaching position. An automatic screw tightener having a control device for operating a tightening head.
可範囲を有し、前記キャリア部の位置と所定のねじ締め
教示位置との差が前記ねじ締めヘッド動作許可範囲以内
になったとき前記ねじ締めヘッドを動作させる手段を有
したことを特徴とする請求項１記載の自動ねじ締め機。2. The control device has a screw tightening head operation permission range, and when the difference between the position of the carrier portion and a predetermined screw tightening teaching position is within the screw tightening head operation permission range, the screw tightening head operation permission range is set. The automatic screw tightening machine according to claim 1, further comprising means for operating a tightening head.
作許可範囲を設定変更可能な手段を有したことを特徴と
する請求項２記載の自動ねじ締め機。3. The automatic screw tightener according to claim 2, wherein the control device has means for setting and changing the operation range of the screw tightening head.
ャリア部の位置の保持を解除させる手段を有したことを
特徴とする請求項１記載の自動ねじ締め機。4. The automatic screw tightener according to claim 1, wherein the control device has means for releasing the holding of the position of the carrier portion after completion of positioning.
の保持と保持解除を作業プログラム内で選択設定できる
手段を有したことを特徴とする請求項４記載の自動ねじ
締め機。5. The automatic screw tightener according to claim 4, wherein the control device has means for selectively holding and holding the position of the carrier portion in a work program.
可時間を有し、前記キャリア部が所定の教示位置に停止
するまでの時間を所定の速度パタ−ンからサンプリング
周期毎に計算し、該時間が前記ねじ締めヘッド動作許可
時間以内になったとき前記ねじ締めヘッドを動作させる
手段を有したことを特徴とする請求項１記載の自動ねじ
締め機。6. The control device has a screw tightening head operation permission time, calculates a time until the carrier portion stops at a predetermined teaching position from a predetermined speed pattern for each sampling cycle, The automatic screw tightening machine according to claim 1, further comprising means for operating the screw tightening head when a time is within the screw tightening head operation permission time.
作許可時間を設定変更可能な手段を有したことを特徴と
する請求項６記載の自動ねじ締め機。7. The automatic screw tightener according to claim 6, wherein the control device has means for setting and changing the screw tightening head operation permission time.
記ねじ締めヘッドを所定の待機位置へ退避移動中前記キ
ャリア部を次の教示位置へ移動させる手段を有したこと
を特徴とする請求項１記載の自動ねじ締め機。8. The control device has means for moving the carrier part to a next teaching position during the retracting movement of the screw tightening head to a predetermined standby position after the screw tightening work is completed. 1. The automatic screw tightener described in 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9161794A JPH07299675A (en) | 1994-04-28 | 1994-04-28 | Automatic screw driving machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9161794A JPH07299675A (en) | 1994-04-28 | 1994-04-28 | Automatic screw driving machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07299675A true JPH07299675A (en) | 1995-11-14 |
Family
ID=14031541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9161794A Withdrawn JPH07299675A (en) | 1994-04-28 | 1994-04-28 | Automatic screw driving machine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07299675A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102601610A (en) * | 2012-03-23 | 2012-07-25 | 上海坤孚企业(集团)有限公司 | Screw locking device |
| US20150370238A1 (en) * | 2014-06-24 | 2015-12-24 | Western Digital Technologies, Inc. | Moveable slider for use in a device assembly process |
| CN106002211A (en) * | 2016-05-10 | 2016-10-12 | 芜湖莫森泰克汽车科技股份有限公司 | Installation control method of glass lifter |
-
1994
- 1994-04-28 JP JP9161794A patent/JPH07299675A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102601610A (en) * | 2012-03-23 | 2012-07-25 | 上海坤孚企业(集团)有限公司 | Screw locking device |
| US20150370238A1 (en) * | 2014-06-24 | 2015-12-24 | Western Digital Technologies, Inc. | Moveable slider for use in a device assembly process |
| US9996071B2 (en) * | 2014-06-24 | 2018-06-12 | Western Digital Technologies, Inc. | Moveable slider for use in a device assembly process |
| CN106002211A (en) * | 2016-05-10 | 2016-10-12 | 芜湖莫森泰克汽车科技股份有限公司 | Installation control method of glass lifter |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20010703 |